Glass fiber drawing mechanism



1954 J. F. COURTNEY ETAL 2,685,763

GLASS FIBER DRAWING MECHANISM Original Filed May 11, 1951 fladsv/azz/a: (Zaire/01a Mejia/m PM 0 W Patented Aug. 10, 1954 PATENT \OFF'IQC E" RadEtke; Chicago; 111., assignors to International a corporation of New Harvester Company,

= Jersey "Original application May 11, 1951, Serial No. 425,883; Divided-and this application June 6;

l 1952;Serial l\To'.' 2945687 Glaims. -1-. f: This invention relates :to av'novel: apparatus for attenuating: a. thermoplastic material and has specific reference to the manufacture of glass fibers-in the making-of: glassastrands andthe like; This application is ca divisionalvof our application Serial tr:225:833;JfiledMay' 11, 1 951, for Glass Fiber DraWingJMecha-nism and Process. 7 Elemental glassfibers c arezcharacterized "by low tensile:- strength; "susceptibility to abrasionz-and fracture and extreme .fragilityand; brittleness. Due to thissnature bf-r-thez-materiala'and the high speed for 1 drawing the 1 material. into fiber. form, extremezd'rfiiculty hastbeen experienced in provid .ing-ta a' satisfactory. drawing" mechanism'zwhich wilhafiord a=' positivegrasp: on 'thevstrand 'without deformation. andiprovideir a1 "sustained substantially-evenpull onstliestrancl to "obtain approxi mately uniform characteristicswith regard to flexibility, diameter; texture, etc; throughout its "length.

zAz/general object of the invention is to devise a. novel drawing mechanism which obtainsf a gentle-grasp on asubstantial length-of a strand and: effects an approximately uniform'pullon the: strand without imposing high transverse "stresses thereon. I

A -further obje'ctis=--to obtain an arrangement which provicles agraspon the strand by" con-'- tinuousl-y 'moving opposed endless surfaces mov- "ing: about predetermined axes in such" manncr as to utilize' the" centrifugar forces" thereon to bias the surfacestowards"eachother and'produce a gras'ping effect onthestrand. v v V -A'- more specific objectis-to provide a drawing devicepresenting" opposed continuous surfaces receiving an extensive length of the strand there- -between-',- at least one-of thesesurfaces being (ii-- -rectlyaotuated and atleast one of thesesurfaces being yieldably urged against the strand by impressing a centrifugal and/or other force thereagainst.

The invention comprehends inone embodiment the provision of a drawing wheel with a peripheral strand engaging surfaceand' a belt biased against an extensive lengthloiiithe surfac a- L'Iihese and other. objects ofiitheinventionwill become more apparent-from the specification and drawings wherein: V

Figure 1 is seasideelevationahview of one form of the invention with environmental components showndiagrammatically.

Describing theinvntion in detail'andreferring first to the embodiment shown in Figure l,

the furnace 2 has a bottom die plate 4 through 2 which the moltenglass in the furnace flows by gravity to form a plurality of filaments [6,10

which are gathered by the operator and manually drawn over an applicator assembly l2a-wh1ch coats each filamentindividually;due tothe fan spread: arrangement thereof, with a coating WhiChflS preferably aplastic The filaments are converged into; a" 'Ve'groove Maofa sheave 16 which associates the filaments It intoa strand [8' while the coating. is;still adherent;- whereby it may coalesce to: form. a bonded mass holding the filaments grouped; in parallel; sheave it maybe mounted as at 20. The strand then extends through a guide forlczzw to the top sidebf drawing wheel '22 which is: actuated" or? rotated by a shaft 24 of a driving motor 26. I The. strand engages the wheel along the circumferential surface 28 and is maintained therea'gainstbymeans of a-be1t'30 which is'yielclably pressedtc assume the arcuate contourof the opposing portion of the di'awingimember 22. The: endless belt 30* is trained-around two sheaves stand 34-, sheave 3 2 being disposed above member 22' and preferably at" one side of the shaft 24, as -seenin Figure 1, on'a preferably fixed axis 36. The sheave 341s "journaled as-at 38 to anarm' or cantilever member lfiintermediate the ends thereof,"the' inner end of member 40 *being rotatably supported on theshaft2'4 and the outer end of member 40 providinga-hook from which maybe supported strand it over an extensive length thereof and 7 surfaces.

It will be understood that the drawing operation is initiated manually by the workman who collects the filaments I 0, m as they issue from the plate 4 and then draws the same over the applicator assembly 12 and then under the gatherer and then through the centering fork 20 and between the grasping surface 28 and the belt 38 while the drawing wheel 22 is rotated in the direction of the arrow. Initially the strand i8 is coarse and relatively inflexible and this portion of a strand after it is discharged from the drawing means is discarded. After the drawing attains the determined rate, the filaments assume desired characteristics, to wit, thin diameter, flexibility and fine textures the strand is passed through a nozzle 46 which is identical with that shown in our companion U. S. application entitled Glass Fiber Drawing Mechanism and Process Serial No. 221,596 filed April 18, 1951.

The nozzle 46 comprises a plurality of parts which are assembled about the thin strand and is positioned in vertical alignment with the vertical tangent coaxial with the strand and passing through a point on a substantially horizontal plane containing the axis of the shaft 24. The nozzle 4'6 is activated by delivering air under pressure therethrough to impress a slipping dynamic tensile force on the strand slightly greater than the speed of discharge of the strand from the drawing member. The mild pulling action of the air nozzle does not exert sufficient force to snap the strand.

In addition to the cantilever arrangement drawing the belt 30 against the strand, the rotation of the belt about its axis produces a centrifugal force which acts transversely of the strand and urges the belt against the strand and the latter into intimate contact with the surface 28 of the drawing element.

The strand is deposited with a directed downward attitude into a container 48 which may comprise a cylindrical drum open at the top and rotated about its central axis by means of a suitable drive arrangement 58 driven by a motor 52. It will be noted that the strand is deposited eccentrically of the axis of rotation of the canaster in order to obtain suitable coping or packaging of the strand.

In the instant design the centrifugal force together with the initial tensioning adjustment grasps the strand, and the strand is drawn on a curved surface over an extensive length thereof. A gentle grasp is achieved together with the requisite frictional development to obtain the desired pull on the material without deforming the material or fracturing the same.

What is claimed is:

1. In a glass fiber drawing apparatus, a rotatable drawing wheel having a peripheral drawing surface, driving means operatively connected thereto, a belt loop having a length in engagement with said surface and having a first end defining an intake with said surface and a second end defining an outlet with the surface, a sheave rotatably supporting each end of the loop, the sheave at said first end rotatable on a fixed axis, a cantilever having one end pivoted on the axis of rotation of said wheel, means rotatably supporting the othersheave on said cantilever intermediate the ends thereof, said other sheave movable with said cantilever on an arc concentric with said surface and wrapping said belt length concentrically about said surface, and variable weight means carried by the cantilever at the other end thereof.

2. In a glass fiber drawing apparatus, a rotatable drawing wheel presenting a peripheral drawing surface, driving means operatively connected to said wheel at the axis of rotation thereof, a belt loop: having va'runwrapped against said surface and-defining a fiber grasping area therewith and affording an intake end upstream of the direction of rotation of said wheel and a discharge end downstream of said direction of rotation of said wheel, rotatable mounting means for each end of the loop, the means at said intake end disposed on a stationary axis, a movable support for the mounting means at said discharge end and pivoted on said axis, of rotation of the wheel and carrying said last-mentioned mounting means adjacent to said periphery and providing path of movement for said last-mentioned mounting means concentrically about said surface.

3. A drawing apparatus according to claim 2 wherein said movable support comprises a cantilever adapted to swing in a direction loosening said run from said surface at said discharge end to dissipate excessive centrifugal action against the belt without disengaging the entire length of said run from said surface.

4. A drawing apparatus according to claim 2 wherein said support comprises a cantilever, and adjustable weight means mounted upon the cantilever to effect a hold down of the belt with said run thereof against said surface.

5. In a drawing apparatus for glass filaments a drawing assembly adapted to attenuate the filaments, comprising a drawing wheel with a peripheral drawing surface adapted to receive the filaments thereagainst, biasing means for snubbing the filaments against the surface and C0111- prising an endless belt loop having a length opposing the surface and pressed thereagainst in grasping relationship to the filaments, and means positioning the belt along the surface comprising a pair of sheaves in the loop at opposite ends of said length, the sheave at one end of said length being carried on a substantially fixed axis, driving means for the wheel connected thereto at the axis of rotation thereof, a support for the other sheave connected thereto and pivoted on said axis whereby said other sheave is swingable in an arc concentric with said surface to obtain a maximum extent of concentric engagement between said length and the surface, and means operatively associated with said support for urging it in a direction engaging the length with said surface, said last-mentioned means being variable to effect adjustment of the biasing load in accordance with the character of the coating applied to the strand to prevent slipping of the strand between the surface and said length of belt.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 81,489 Fuller Aug. 25, 1868 1,595,818 Bliss Aug. 10, 1926 2,225,667 Staelin Dec. 24, 1940 2,323,684 Simison July 6,. 1943 2,448,499 Swann Aug. 31, 1948 FOREIGN PATENTS Number Country Date 384,822 Great Britain Dec. 15, 1932 

